There are a number of scenarios in which it may be advantageous to assign a logical computing entity to a particular physical computing entity. One such example scenario may occur when customer accounts purchase computing resources such as virtual machine instances (“instances”). Such instances may be launched within respective data centers, which are collections of physical computing devices. In some cases, an account may launch instances in one or more logical zones, and each such logical zone may be assigned to a corresponding data center such that the account's instances within the logical zone are launched in the corresponding data center. However, the logical to physical assignments may vary between accounts. For example, for Account 1, logical zone 1 may be assigned to data center 1. By contrast, for Account 2, logical zone 1 may be assigned to data center 2. Thus, when Account 1 launches an instance in logical zone 1, the instance will actually be launched in data center 1. By contrast, when Account 2 launches an instance in logical zone 1, the instance will actually be launched in data center 2. Thus, in such scenarios, account owners may be unaware of the exact location and identity of the underlying data center in which their instances are launched.